The new methane-fueled Raptor engine developed by US SpaceX aerospace company for its Starship interplanetary craft has outperformed the Russian RD-180 rocket engine in terms of pressure level in the combustion chamber, SpaceX CEO Elon Musk said on Monday.

"Raptor reached 268.9 bar today [approximately 274.2 kilograms of power per square centimeter], exceeding prior record held by the awesome Russian RD-180," Musk said on Twitter, according to sputniknews.com.

On February 4, Musk said that SpaceX had conducted the first test firing of Raptor.

Russian liquid-fuel rocket engine RD-180 is used in the first stage of the US Atlas-5 rocket. According to Russian rocket engine manufacturer Energomash, the pressure in the combustion chamber of the RD-180 is 261.7 kilograms of power per square centimeter.

On January 31, Musk posted a couple of images on Twitter showing a Starship Raptor engine and saying SpaceX was preparing to test fire it at its Texas facility.

So far, SpaceX has completed the assembly of a stainless Starship Hopper prototype meant for takeoff and landing tests.